Book/Report

FZJ-2018-03154

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Migrations- und Akkumulationsgeschichte der Erdöle des nördlichen Oberrheingrabens und deren Beziehung zur Diagenese der klastischen Speichergesteine

Rückheim, J. (Corresponding author)FZJ*

1989
Kernforschungsanlage Jülich, Verlag Jülich

Please use a persistent id in citations: http://hdl.handle.net/2128/18689

Report No.: Juel-2307

Abstract: Based on an interdisciplinary research program, i.e. the application of both organicgeochemical and petrographic methods, this thesis was intended to elucidate themigration- and accumulation history of petroleum in the Northern Rhinegraben, and its relationship to sandstone diagenesis. Geochemical analyses of the reservoired oils revealed considerable variations in the oil composition within the Echo/Tangosierra oilfield. These include variations in gross composition, n-alkane distribution and molecular maturity. The compositional heterogeneities change systematically with the petrophysical properties of the reservoir rocks, e. g. lower maturity oils are restricted to low porosity/permeability intervals and vice versa. Kinetic models for both hydrocarbon generation and kerogen maturation in the source rocks were used to reconstruct the accumulation history of the Echo/Tangosierra oilfield. To explain the variations in oil composition an accumulation model is proposed. According to the model lower maturity petroleum first migrated into the high-porosity intervals of the reservoir. During the later stages of oil accumulation petroleum of increasingly higher maturity entered the reservoir. The increasing height of the oil column and hence the increasing buoyancy caused the early less mature accumulation products to be displaced into the fine capillaries of the low-porosity intervals. This process led to the variations in oil character observed today. Petrographic and geochemical analyses of the reservoir sandstones have been applied to reconstruct the diagenetic history of the reservoir rocks. Kaolin A, quartz and illite are considered to be early diagenetic, having formed under the influence of syn-depositional formation waters. During the later stages of reservoir diagenesis, kaolin B and ferroandolomite,/ankerite were formed. The latest diagenetic processes are characterised by the albitisation of K-feldspar, the illitisation of kaolins and the formation of secondary porosity. By integrating the results of the different methods applied in this study (geochemistry/petrophysics, petrography), it was possible to relate the history of hydrocarbon generation and kerogen maturation to the diagenetic evolution of the reservoir rocks. Moreover this study has shown that there is a causal link between the transformation of the organic material in the source rocks and the diagenetic processes in the reservoir rocks of the Echo; Tangosierra oilfield.

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Contributing Institute(s):

1. Publikationen vor 2000 (PRE-2000)

Research Program(s):

1. 899 - ohne Topic (POF3-899) (POF3-899)

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Database coverage:

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